UNITED NATIONS – The U.N. Security Council has approved a surge of African Union troops to fight al-Shabab militants in Somalia.

The council voted unanimously Tuesday to authorize almost 4,400 more African Union troops and massive U.N. assistance to break the stalemate in Somalia, where top U.N. officials say the war against Islamic militants has "ground to a halt."

The council authorized an African Union force of 22,126 troops, up from 17,731.

The surge is meant to provide a short-term enhancement to the force known as AMISOM. After 18 to 24 months, the U.N. wants to hand over the fighting to the Somali army and send a U.N. peacekeeping mission to replace the AU force.

The resolution also approves 12 new military helicopters from troop-contributing countries.